下颌神经管的解剖结构

背景:在下颌后牙种植术中,由于下颌神经管走行于下颌骨体内,有时可损伤下齿槽神经,因而制约了牙种植术的应用。 因此,牙种植术的应用需详细了解下颌神经管的解剖结构。 目的：观察下颌神经管在下颌骨内的走行及管内的解剖结构。 方法：共纳入15具成人牙下颌骨标本与4具新鲜下颌骨动脉灌注标本。纳入对象均牙列完整,后牙无缺失,牙槽骨无吸收。测量15具成人牙下颌骨标本下颌管走行及其管腔各径长度,包括下颌管横径与纵径,下颌管至上下内外缘距离。观察4具新鲜下颌骨动脉灌注标本管内下颌神经管内神经、血管位置关系。 结果与结论：下颌管内缘至舌侧骨板的距离比下颌管外缘至颊侧骨板距离短(P < 0.01);下颌管上缘至牙槽嵴顶的距离较下颌管下缘至下颌骨下缘的距离大(P < 0.01)。表明下颌管在下颌骨体部走行中偏舌侧、偏下颌骨下缘。下颌神经管在下颌骨体部的部分横径小于纵径(P < 0.05),亦即下颌管截面形态为上下径略长的椭圆形。神经管横纵径于前后牙位区差异无显著性意义。实验还发现在暴露的下颌管腔中下牙槽神经及伴随血管有一层被膜包绕成神经血管束,血管位于神经上方,而且位置恒定,并发出小分支包绕神经。结果提示,下牙槽血管神经束在下颌管内走行中血管位于神经之上。     

Anatomic and radiologic course of the mandibular incisive canal

The purpose of this article was to define the anatomic and radiographic courses of the incisive mandibular canal and discuss its clinical significance. The study group comprised of 46 hemimandibles fixed in formalin. After radiographic examination, the buccal cortical plate of the mandible was removed leaving the bony frame of the incisive bundle intact. The morphology of the bony walls of the canal was evaluated, as having complete, partial, or no cortical walls. The course of the intraosseous pathway of the canal and its diameter in four different locations were recorded. An incisive bundle was anatomically found in all hemimandibles, travelling within a canal with complete (n = 10), partial (n = 27), or no (n = 9) bony cortical borders. The diameter of the canal ranged from 0.48 mm to 2.9 mm. Radiographically, the canal was either well defined (n = 11, 24%), poorly defined (n = 15, 32%), or undetectable (n = 20, 44%). A statistically significant correlation was found between the anatomic structure of the incisive canal bony borders and its radiographic detectability (p = 0.043). No correlation was found between the anatomic and radiological width of the incisive canal diameter. An incisive canal with a large diameter could have an important role in successful osteointegration and prevention of postoperative sensory disturbances. According to the present study, the ability to interpret the incisive canal from conventional radiographs is limited. Therefore, it is recommended to use conventional tomographs or computerised tomographic dental scans for better imaging of the intermental foraminal area.     

Morphological changes in the position of the mandibular foramen in dentate and edentate Brazilian subjects

This study assessed the mandibular foramen (MF) position variability in dentate and edentate Brazilian mandibles. Eighty dentate and 79 edentate mandibles of unknown sex were measured bilaterally using a digital caliper (0.1‐mm precision). Horizontal linear measurements (HM) were done from the MF to the anterior border of the mandibular ramus (MF‐A) and from the MF to the posterior border of the mandibular ramus (MF‐B). Vertical linear measurements (VM) were done from the MF to the most inferior point of the mandibular notch (MF‐C) and from the MF to the inferior border of the mandibular ramus (MF‐D). Data were analyzed by two‐way ANOVA (alpha = 5%). The HM means and standard deviations (±SD) for MF‐A were, edentate right (ER): 17.5 (±3.2) mm, edentate left (EL): 17.4 (±3.4) mm, dentate right (DR): 19.2 (±3.6) mm, and dentate left (DL): 18.8 (±3.8) mm. The means (±SD) for the MF‐B measurements were, respectively, ER: 12.8 (±2.4) mm, EL: 12.9 (±2.3) mm, DR: 14.2 (±2.4) mm, and DL: 13.9 (±2.6) mm. The VM values for the MF‐C measurements were, ER: 23.4 (±3.8) mm, EL: 22.9 (±3.7) mm, DR: 23.6 (±3.1) mm, and DL: 23.1 (±3) mm, and for the MF‐D measurements, ER: 26.4 (±4.2) mm, EL: 26.4 (±4) mm, DR 28.3 (±3.9) mm, and DL 28 (±3.8) mm. Side had no influence (p>0.05) on any edentate or dentate mandible measurement. Dentate mandible measurements showed statistically significant differences compared to the edentate mandibles, except for MF‐C. The mandibular foramen position changes with loss of teeth and this variability may be responsible for occasional failure of inferior alveolar nerve block. Clin. Anat. 23:394–398, 2010. © 2010 Wiley‐Liss, Inc.     

下颌神经管全长三维走向的测量及其临床意义

目的　研究下颌管的全长走行位置及其与四周骨板的毗邻关系 ,为临床下颌手术提供解剖学依据。方法　对14 0侧成人下颌骨进行冠状、矢状及水平三维剖面的测量。找出下牙槽神经管全长在下颌骨中走行的基本位置及其与四周骨松质、骨皮质的毗邻关系值。结果　下牙槽神经管在下颌骨中走行虽有变化 ,但下颌管全长的总体走行是紧贴着舌侧骨板 ;在下颌第一、二磨牙区下颌管走行与下颌下缘成平行状 ;在近颏孔时才折转向外和向颊侧出颏孔。结论　在牙种植术、下颌各类截骨术中按正常解剖方位并侧重于颊侧骨板操作 ,可以避免损伤下牙槽神经血管。     

Anastomosis between the inferior alveolar artery branches and submental artery in human mandible

The mental artery displays several branches internal to the anterior region of the mandible as confirmed by macroscopic observation and computed tomography. The inferior alveolar artery formed complex branches and divided into mental and incisive branches, which were found in the right internal side of the mandible of one male cadaver (88 years old). The branches of these two arteries ran through the bony lingual canal to the lingual foramen between the canine and premolar region of the inner surface of the mandible body, where they emerged to enter the mylohyoid and anterior belly of the digastric muscles and communicate with the submental artery. The observation of the anastomotic artery is considered important for surgical placement of dental implants in the mandibular region.     

下颌角肥大整形术相关解剖

目的 精细解剖下颌角周围软组织结构及下颌神经管,为下颌角肥大整形术提供解剖学参考。 方法 20例大体标本,观察及测量面动静脉、面神经下颌缘支及咬肌区的血管和神经。据下颌骨表面骨性标志定位5条径线,测量该5条径线上下颌神经管在下颌骨中的位置。计算各软组织结构和下颌神经管的安全范围。 结果 面动脉距下颌角点为23.18～36.28 mm,距咬肌前缘为-9.51～9.27 mm。面静脉距离下颌角点为17.79～32.03 mm。面神经下颌缘支贴近下颌角部及下颌骨下缘走行,距离下颌角点为-8.57～10.70 mm,而咬肌前缘下颌缘支距下颌骨下缘为-8.83～11.06 mm。咬肌的血供主要有面动脉咬肌支、颈外动脉咬肌支、上颌动脉咬肌支及面横动脉咬肌支这四大来源。咬肌神经多与咬肌动脉伴行进入咬肌。下颌神经管在5个截面中距离下颌骨外侧点分别大于10.50 mm、14.72 mm、15.60 mm、8.53 mm、6.74 mm。 结论 在剥离下颌角区软组织时,注意对咬肌前缘面动脉、面神经下颌缘支及下颌角点附近面神经下颌缘支的保护。去除咬肌的最佳层次为咬肌深层中份最厚点及中下份。而在截骨或劈骨时,根据下颌神经管的安全范围,可在下颌骨颊侧骨板快速画出一条指导性的安全线。     

Correlation of mandibular impacted tooth and bone morphology determined by cone beam computed topography on a premise of third molar operation

Purpose

To determine the width and morphology of the mandible in the impacted third molar region, and to identify the location of the mandibular canal prior to planning impacted third molar operations.

Methods

Cone beam computed tomography (CBCT) data of 87 mandibular third molars from 62 Japanese patients were analyzed in this study. The width of the lingual cortical bone and apex-canal distance were measured from cross-sectional images in which the cortical bone was thinnest at the lingual side in the third molar region. Images were used for measuring the space (distance between the inner border of the lingual cortical bone and outer surface of the third molar root), apex-canal distance (distance from the root of the third molar tooth to the superior border of the inferior alveolar canal) and the cortical bone (width between the inner and outer borders of the lingual cortical bone).

Results

The means of the space, apex-canal distance and lingual cortical width were 0.31, 1.99, and 0.68 mm, respectively. Impacted third molar teeth (types A–C) were observed at the following frequencies: type A (angular) 37 %; type B (horizontal), 42 %; type C (vertical), 21 %. The morphology of the mandible at the third molar region (types D–F) was observed as: type D (round), 49 %; type E (lingual extended), 18 %; and type F (lingual concave), 32 %.

Conclusions

The width and morphology of the mandible with impacted teeth and the location of the mandibular canal at the third molar region could be clearly determined using cross-sectional CBCT images.     

The mandibular canal of the edentulous jaw.

The morphology of the mandibular canal after loss of teeth has received little detailed attention. Improved documentation of this topic would allow better interpretation of dental radiographs and would enable those engaged in tooth implantation to better understand the nature of the tissue into which the prostheses are placed. In this study on mandibles from seven dissecting room cadavers panoramic radiographs usually showed the mandibular canal clearly, an incisive canal less so. The wall of the mandibular canal was similar in dentate and edentulous mandibles, and was highly perforated, as suggested by Cryer (Anderson et al., 1991). In edentulous specimens, it was composed mainly of cancellous bone with only occasional single osteons. The inferior alveolar nerve near the mandibular foramen was a large trunk, consisting of three to four nerve bundles with connective tissue sheaths. It became more loosely arranged toward the mental foramen. Medial to the mental foramen, the nerves were frequently in the form of small bundles in the marrow. Any incisive canal was ill-defined and neurovascular bundles, when present, ran through a labyrinth of intertrabecular spaces.     

Anatomical configuration of the inferior alveolar neurovascular bundle: a histomorphometric analysis

Purpose

The inferior alveolar neurovascular bundle (NVB) is important in implant placement and many other surgeries in dentistry because it is a major supplier of sensation and blood to the mandible via the mandibular canal. The purposes of the present study were to determine the areas and diameters of the NVB, the inferior alveolar nerve (IAN), and the inferior alveolar artery (IAA), and to verify the buccolingual location of the mandibular canal.

Methods

The anatomical configuration of the NVB was examined by histomorphometrically analyzing 20 embalmed dentulous hemimandibles. The areas and maximum horizontal and vertical diameters of the NVB, IAN, and IAA were measured according to tooth region. The distances from the internal border of the mandibular canal to the outer surface of the buccal and lingual cortical plates were also measured.

Results

The areas of the vertically oval-shaped NVB and IAN appeared to be constant between the molar and premolar regions, which contain the mental branch, and decreased sharply in the lateral incisor after branching off of the mental branch via the mental canal. The mandibular canal was located close to the lingual cortical plate in the posterior tooth region before passing through the mental canal, immediately after which it was situated quite close to the buccal cortical plate, and then closer to the middle toward the anterior tooth region.

Conclusions

The findings of this study provide useful anatomical information that should help to minimize the risk of injury to the NVB during surgical procedures in the mandibular region.

     

A Novel Method for Observation of the Mandibular Foramen: Application to a Better Understanding of Dental Anatomy

Cone‐beam computed tomography gives us much useful morphological information about the mandibular bone. Many studies of the mandible include findings from this technique. However, there have been no endoscopic studies of the mandible. Sixteen sides of eight dry mandibles resected from cadavers (age range 38–83 years) were examined by endoscopy. The head of the endoscope was 2.0 mm in diameter. We examined the mandibular foramen, lingula, mylohyoid groove, and mandibular canal. The mylohyoid grooves showed variations such as double grooves and canals. The mandibular lingula was located superior or medial to the the mandibular foramen. In a single case, the medial wall inside the mandibular canal showed a porous surface. The retromolar canal was observed in three sides. None of the images in the present study have been seen in other studies. Observation of the retromolar canal from the mandibular canal in particular can help dental students as well as oral and maxillofacial surgeons to understand its morphology. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1875–1880, 2017. © 2017 Wiley Periodicals, Inc.     

The position of the mandibular canal and histologic feature of the inferior alveolar nerve

The inferior alveolar nerve is the one of the large branches of the mandibular division of the trigeminal nerve. It is vulnerable during surgical procedures of the mandible. Despite its importance, no anatomical and histological examination has been conducted to provide a detailed cross‐sectional morphology of the mandibular canal according to dental status. Therefore, the present study aimed to identify the position of the mandibular canal through direct measurement and to determine the branches of the inferior alveolar nerve through histologic examination. The area between the anterior margin of the third molar and the anterior margin of the second premolar of dentulous, partially dentulous, and edentulous hemimandible specimens (n = 49) from 26 human cadavers was serially sectioned into seven segments, and specific distances were measured using digital calipers. Following this, 5‐μm cross‐sections were prepared along the mandibular canal and mental foramen, and examined by fluorescence microscopy. The mandibular canal was located at a mean distance of 10.52 mm above the inferior margin of the mandible. The mean maximum diameters of the mandibular canal, inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein were 2.52, 1.84, 0.42, and 0.58 mm, respectively. This study found that the inferior alveolar nerve often gives rise to several branches at each level (range 0–3). To minimize the risk of injury, knowledge of the small branches of the nerve and of the detailed findings regarding the position of the mandibular canal reported here should be considered when planning mandibular surgery, especially during implant placement. Clin. Anat. 23:34–42, 2010. © 2009 Wiley‐Liss, Inc.     

Appearance of the mandibular incisive canal on panoramic radiographs

Panoramic radiographs are routinely used in the dental office for various diagnostic purposes. This study aimed to evaluate the visibility of neurovascular structures in the mandibular interforaminal region on such radiographs. Panoramic radiographs were obtained with a Cranex Tome (Soredex) from 545 consecutive patients using a standard exposure and positioning protocol. For visibility scoring of neurovascular structures, a four-point rating scale was used. The mandibular canal and the mental foramen could be observed in the majority of the cases with good visibility. The lingual foramen was visualized in 71% of the cases, with good visibility in 12%. An incisive canal was identified in 15% of the images, with good visibility in only 1%. An anatomical variation to be considered is the anterior looping of the mental nerve (in 11% of images). Panoramic radiographs can be used for visualization of the mental foramen and a potential anterior looping but not for locating the mandibular incisive canal. To verify its existence for preoperative planning purposes, cross-sectional imaging modalities (HR-CT or spiral tomography) should be preferred.     

颅底外面枕骨基底部及周边骨性结构的测量和临床意义

目的为斜坡区肿瘤手术提供解剖资料。方法20例整颅,10例行水平切面,10例行正中矢状切面。测量切牙孔、前鼻棘、后鼻棘、枕骨大孔前端、枕髁前端、卵圆孔、破裂孔、颈动脉管外口及舌下神经管外口的内侧缘至咽结节的距离;测量卵圆孔、破裂孔、颈动脉管外口及舌下神经管外口的内侧缘至正中线的距离;测量枕骨基底部颅底外面的长径、枕骨大孔纵径(FML)、枕骨大孔前正中点与枕髁后缘连线垂直距离(AOCP)、枕髁轴径(OCA)、枕髁间距。结果切牙孔后缘、前鼻棘、后鼻棘、枕骨大孔前端、枕髁前端、卵圆孔、破裂孔、颈动脉管外口及舌下神经管外口的内侧缘至咽结节的距离分别为(mm):72.12±4.25、77.77±3.89、33.73±2.07、13.14±1.91、15.71±1.74、27.51±2.12、15.98±1.98、25.93±2.23、19.15±1.49。卵圆孔、破裂孔、颈动脉管及舌下神经管外口的内侧缘至中线的距离分别为:25.55±1.63、11.72±1.70、25.75±1.98、17.41±1.41。枕骨基底部颅底外面长径、FML、AOCP、OCA、枕髁间距分别为(mm):28.80±2.67、35.84±2.59、17.10±1.13、24.55±2.35、21.07±1.92。结论经口咽至斜坡区的手术入路中,开骨窗时安全范围是以咽结节为中心,以15mm为半径做斜坡磨除;也可以做矩形骨窗,即以咽结节为中心开一长(高)25mm×宽20mm的骨窗。     

下颌管与下颌后牙的位置关系及临床意义

目的: 为下颌牙种植术等临床口腔外科提供解剖学基础。方法：选取新鲜下颌骨标本10例、成人全牙下颌骨标本18例和20名全牙志愿者,分别暴露出下牙槽神经血管束、下颌管与下颌后牙牙根和CT连续扫描后进行三维重建。观察下牙槽神经、血管的排列关系,用游标卡尺和CT三维重建工作站分别测量下颌后牙牙根至下颌管上壁的距离。结果：下颌管自牙槽窝下方走行,其舌侧骨板较厚;下颌管内的下牙槽血管位于下牙槽神经上方。下颌磨牙的远中根至下颌管的距离均较近中根近。在标本及影像上的第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根至下颌管上壁的距离分别为(8.36±2.34)　mm和(8.42±2.42)mm、(7.36±2.21)mm和(7.52±2.18)mm、(3.22±1.40)mm和(3.36±1.85)mm、(2.96±1.54)mm和(2.84±1.55)mm、(3.64±1.72)mm和(3.88±1.76)mm。结论：（1）下颌后牙至下颌管的距离以第2磨牙最近,由近及远依次为第2磨牙、第1磨牙、第3磨牙、第2前磨牙和第1前磨牙。（2）对选择适宜长度的牙种植体,避免牙种植体损伤下牙槽神经等具有重要意义。     

Morphological Changes in the Mandible of Male Mice Associated With Aging and Biomechanical Stimulus

Degenerative changes in the temporomandibular joint (TMJ) associated with aging can affect mandibular shape and reduce growth potential when stimulated by functional appliance therapy. This study was designed to evaluate the morphological changes in the mandibles of male mice associated with aging and biomechanical stimulus. Every 3 days over the course of 1 month, the lower incisors were trimmed by 1 mm to induce mandibular advancement (MA) when the animal was feeding. The left mandibles of the 23 experimental and 27 control animals were subsequently dissected, and digital images were obtained to analyze nine linear/angular measurements. Because mandibular morphology depends on the maintenance of condylar cartilage, the surfaces of the condylar cartilage and the ascending ramus of the mandible were also analyzed by scanning electron microscopy (SEM). The linear measurements of the mandible showed changes according to age in the control group and a growth response in the mandibular condyle in 7‐ and 15‐month‐old mice after MA. Moreover, SEM analysis revealed depressions in the anterior region of the condylar cartilage and inclined vascular grooves in the ascending ramus in the 7‐ and 15‐month‐old experimental mice. Although the growth potential is reduced in mice after 6 months of age, the results showed that continuous growth of the mandible occurs after maturation, except in the condyle, and that biomechanical stimulus of the TMJ of male mice leads to condylar growth. These results suggest that mature and old individuals can favorably respond to maxillary functional orthopedic therapy. Anat Rec, 292:431–438, 2009. © 2009 Wiley‐Liss, Inc.     

下颌管的应用解剖及临床意义

目的:为下颌牙种植术等临床口腔外科提供解剖学基础.方法:选取下颌骨标本10例、新鲜下颌骨标本10例和成人全牙下颌骨标本20例,分别暴露出下颌管截面、下牙槽神经血管束和下颌管与下颌后牙牙根.观察下颌管的形态、走行和下牙槽神经、血管的排列关系,用游标卡尺测量下颌后牙牙根尖至下颌管上壁的距离.结果:下颌管呈椭圆形,自磨牙牙根尖舌侧和前磨牙牙根尖颊侧的下方走行;下颌管内的下牙槽血管位于下牙槽神经上方.下颌后牙牙根至下颌管的距离以第2磨牙最近,由近及远依次为第2磨牙、第1磨牙、第3磨牙、第2前磨牙和第1前磨牙;下颌磨牙的远中根至下颌管的距离均较近中根近.第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根至下颌管上壁的最短距离分别为(8.19±0.87) mm(左)和(8.29±0.88) mm(右)、(7.38±0.85) mm、(3.30±0.66) mm、(2.98±0.77) mm(左)和(2.92±0.75) mm(右)、(3.82±0.63) mm(左)和(3.86±0.64) mm(右).结论:下颌管的应用解剖对选择适宜长度的牙种植体,避免牙种植体损伤下牙槽神经等具有重要意义.     

Neural symmetry and functional asymmetry of the mandible

Even in the absence of malformation or skull base asymmetry, the mandible may be physiologically asymmetric and this remains a major challenge in the orthodontic treatment. The mandible is a bone formed by a primary subunit, i.e., the neural part, with different functional secondary subunits, so we suggest that in a normal mandible the asymmetry was caused by the secondary functional subunit and the neural part is nearly symmetric. Eighty-three dry human mandible samples were studied. The measurements of the size of the mandible (corpus, ramus, mandible notch, condylar process, the angle of the mandible) and the neural subunit (the mandibular canal and the position of the mental and mandibular foramina) were measured bilaterally. The left and right sides were compared according to the dental status: 60 dentate and 23 edentulous mandibles. The calculation of the symmetry was based on the paired Student t test, the absolute difference |R−L| and the relative absolute difference |R−L|/|R+L|×100. The mandibular canal and the position of the foramina were symmetric, except for the position of the mandibular foramen in relation to the mandible notch. The symmetry was not modified by the dental status. The total length of the mandible and the length of the ramus were greater on the left side independently from the dental status. The length of the corpus and the mandible angle were symmetric in each group. The mandible notch was always asymmetric and its height was greater in the dentate group. The condylar process was the most asymmetric structure in each group. The primary subunit of the mandible, surrounding the mandibular canal, is a symmetric component of the mandible and is not modified by the dental status. The angle of the mandible between the corpus and ramus is another symmetric parameter that is important for the facial architecture. The ramus and especially the mandibular notch as well as the condylar process are the most asymmetric subunits influenced by the functional matrices.     

The appearance of foramen in the internal aspect of the mental region of mandible from Japanese cadavers and dry skulls under macroscopic observation and three-dimensional CT images

The lingual canal with foramen displays different appearances on the internal surfaces of mandible as confirmed by macroscopic observation and computerized tomography (CT). The lingual canal was observed in the inside of mental region run to the outside of lingual foramen, which is extend internally from mandibular canal in right and left sides of the mandible in cadavers (13 sides out of 88 sides) and in dry skulls (43 out of 94 sides) examined. The spinal foramen connected with mental canal occurred at the midline of mandible in 6 cases (6 out of 47 cases) in dry skulls. In this small foramen, the inferior alveolar artery give some branches to the inside of mental region at the anterior mandible and which may be run pass through the lingual canal to the lingual foramen, where they emerge to enter the mylohyoid or anterior belly of digastric muscles. The observations of these are important considerations for surgical placement of dental implants in the region in the mandible.     

面神经下颌缘支的应用解剖

目的了解面神经下颌缘支的正常层次解剖位置,为涉及面侧区和颌下区的美容外科手术提供临床应用解剖学资料。方法解剖33具（共66例）成人尸体标本的头颈部标本,观察了面神经下颌缘支的分支类型、走行、与面动脉的位置关系以及穿出腮腺处和与面动脉的交叉处的体表位置。结果面神经下颌缘支为1-2支,以单干型居多,约占58%,大多行于下颌骨下缘上方约占44%,行于骨下缘下方者占5%。未发现面神经下颌缘支不与面动脉交叉,位置在均下颌角下缘上、下方约0.5-1 cm范围内。面神经下颌缘支经过面动脉的浅面和深面者分别占89%和6%;面神经下颌缘支穿出腮腺处的体表位置分别在下颌角上方和下颌支后缘前方1 cm交点附近,面神经下颌缘支与面动脉交处距下颌支后缘约4 cm,距下颌骨下缘约1 cm。结论面神经下颌缘支的毗邻和行程关系较为复杂,了解其与周围结构的重要位置关系,可以减少美容外科手术因神经损伤造成下唇及口角功能障碍的发生。     

Shape,height, and location of the lingula for sagittal ramus osteotomy in Thais

This study aims to investigate the shape, height, and location of the lingula in relation to surrounding structures for sagittal ramus osteotomy. Dried Thai mandibles were studied and compared with other races. From both sides of 92 mandibles, the shape of the lingula was classified into triangular, truncated, nodular, or assimilated types. Of 92 mandibles, 146 sides with at least a premolar and a molar on the same side were selected for distance measurement. Height of the lingula was measured from the lingular tip to the mandibular foramen. The location was determined by five distances from the lingular tip to: the anterior and the posterior borders of the mandibular ramus, the mandibular notch, the distal surface of the mandibular second molar, and the occlusal plane. The results showed that truncated lingulae were most frequently found (46.2%) and most appeared to be bilateral (71.7%). Triangular, nodular, and assimilated shapes presented in 29.9%, 19.6%, and 4.3%, respectively. The mean lingular height was 8.2 ± 2.3 mm. The lingula was located at 20.6 ± 3.5 mm from the anterior border of the mandibular ramus and 16.6 ± 2.9 mm from the mandibular notch. In the majority of the mandibles studied, the lingula was located above the occlusal plane. In conclusion, the shape and metric characteristics of the lingula in relation to surrounding structures in Thais vary from other races. All parameters associated with the lingula should be considered for sagittal ramus osteotomy to avoid intraoperative complications. Clin. Anat. 22:787–793, 2009. © 2009 Wiley‐Liss, Inc.